Engine exhaust manifold cover



Jan. 27, 1970 ,1. D. NEWKIRK ENGINE EXHAUST MANIFOLD COVER Filed Dec. 18, 1967 i l1 r INVENTOR. John D. Newkirk Attorneys United States Patent 3,491,849 ENGINE EXHAUST MANIFOLD COVER John D. Newkirk, Hayward, Calif., assignor to Tiffany Brown Filed Dec. 18, 1967, Ser. No. 691,305 Int. Cl. F01m 1/24 US. Cl. 18133 4 Claims ABSTRACT OF THE DISCLOSURE This specification discloses a cover consisting of an outer metal skin and a sound insulating and sound sup pressing material held against the skin by a resilient expanded wire sheet member which is spring biased by bending.

BACKGROUND OF THE INVENTION SUMMARY The gist of the invention is the discovery that a cover consisting of an outer skin of metal, and an insulating material attached to the exhaust manifold gave excellent heat insulation and sound suppressing characteristics.

Objects of the present invention are to provide a cover for the exhaust portions of engines which:

(1) Are inexpensive to manufacture and install,

(2) Reduce the heat normally radiated from the exhaust manifold,

(3) Reduce the engine noise, and

(4) May be removed and replaced quickly and easily without damage to the cover.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a side elevation of a diesel engine mounted on a trailer shown in phantom line with the cover of the present invention installed on the exhaust manifold.

FIGURE 2 is a side elevation of the cover shown in FIGURE 1 on an enlarged scale with portions removed and shown in cross section.

FIGURE 3 is a bottom view of the device shown in FIGURE 2 taken substantially along the line 3-3.

FIGURE 4 is a cross section of the device taken substantially along the line 4-4 of FIGURE 3 and shown on an enlarged scale.

FIGURE 5 is an enlarged partial side view of the device taken substantially along the line 5-5 of FIG- URE 4.

FIGURE 6 is an alternate form of the invention showing a cross section of an exhaust pipe from a gas turbine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention consists briefly of an elongated thin sheet member 1 curved along its vertical axis at least partially covering a sound transmitting member, a sound absorbing material 2 held in contact with the sheet member, spring biasing means 3 holding the sound absorbing material against the sheet material and permitting passage of sound Waves therethrough, and means 4 holding the sides of the sheet material in spaced relation.

Where sound suppression only is desired the sheet material forming the skin of the hood may be made of any of various flexible materials. Where a hood is required to also insulate from intense heat and where vibration is also a factor such as the exhaust manifold of an engine, it is preferable to use a metal such as aluminum. For more work 0.025 aluminum semi-alloy is satisfactory. I have found that other materials under the intense heat and vibration deteriorate too rapidly. I have further found that aluminized asbestos cloth or merely asbestos cloth or merely asbestos cloth may be substituted for the aluminum. The cloth is stiffened by placing a layer of hardware cloth between the Fiberglass insulation and the asbestos cloth.

Several types of sound suppressing material may be used but where intense heat is present such as from an exhaust manifold, Fiberglas is the best material.

The spring biasing means is here shown as a resilient material formed with openings permitting relatively unobstructed transmission of sound waves and of heat if this is present. This element could be made of plastic where heat is not a factor and perforated to permit transmission of the sound waves therethrough. Where the device is used to insulate against heat as well as sound, a metal is perferable such as standard metal hardware cloth as illustrated in the drawings.

FIGURE 4 shows the hood in the general shape of a horsehoe or an arch. The ends of the sheet are held in spaced relation by means of a strap 4. These straps may be placed at intervals along the length of the hood as required.

The sides of the insulation material can be held in place by clips or other means but preferably the sides of the sheet member are turned inwardly forming channels 6 and 7 for the receipt of the sides. These channels may also hold the sides of the spring biasing means. In addition, the formation of the channels, adds to the rigidity of the hood.

In FIGURE 6, another form of the invention is shown in which the sheet material 1, insulating material 2' and spring biasing means 3 form a complete enclosure around a heat and sound transmitting member such as an exhaust member 8 from a gas turbine. The mounting is somewhat different to provide for the very high frequency vibration from the gas turbine. I have found that the hood. is protected from deterioration by use of a polyurethane channel member 11 to isolate the vibration of the exhaust from the hood.

One of the first uses of the hood of the present invention was on large mobile diesel generator sets in which the motor was mounted on a wheeled trailer 12 and then covered with sides 13 and roof 14. The trailers were provided with sound insulating material but the sound level was oppressive. Applicant constructed the hood as shown in the drawing and as described hereinabove and placed it on the exhaust manifold. A marked decrease in sound level was experienced. Furthermore, the hood has excellent heat absorbing characteristics and it was found that a person could place his hand on the hood without being burned.

Since maintenance men must work inside the trailers while they are running, the comfort and safety features were greatly increased. In practice, the hood shown in FIGURES 1, 2, 3, 4 and 5 is merely placed over the exhaust manifold in sections which are later fastened together. The hood rests immediately on the manifold without special hangers. After the sections are assembled, the straps are placed under the exhaust manifold, and the side edges of the hood fastened together. The straps add 3 rigidity to the hood as well as preventing dislodgment of the hood from the exhaust manifold.

Iclaim:

1. An insulating and sound suppressing hood comprising:

(a) an elongated thin sheet metal member having a curved transverse cross section sprung inwardly providing an arcuate interior surface and the side thereof being spaced from one another and forrmed with inwardly upturned flanges;

(b) tie members spanning the distance between said sides and joining the sides thereby holding said member in said arcuate shape:

(c) a sheet of sound absorbing and heat insulating material in registration with said arcuate interior surface; and

(d) elongated resilient means sprung against said sound absorbing and heat insulating material for holding the same against said sheet member, said sides of said resilient means being held by said upturned flanges.

2. A hood as defined in claim 1 wherein:

(a) said resilient means is a wire mesh coextensive with said insulating material.

3. A hood as defined in claim 1 wherein:

(a) said sound absorbing and heat insulating material is Fiberglas.

4. A hood as defined in claim 1 wherein:

(a) said distance between said sides of said member is less than the diameter of said curved cross section.

References Cited UNITED STATES PATENTS 1,547,532 7/ 1925 Taylor. 1,740,995 12/ 1929 Midgley. 1,899,403 2/1933 Venzie. 2,741,325 4/1956 Brown et a1 181-62 XR 2,913,870 11/1959 Lashley. 3,021,914 2/1962 Wilson. 3,043,097 7/1962 Inman et a1 181-72 XR 3,061,039 10/1962 Peters. 3,395,775 8/1968 Smith.

FOREIGN PATENTS 448,081 4/1948 Canada.

561,876 10/1932 Germany.

- 357,147 9/1931 Great Britain.

405,380 2/ 1934 Great Britain.

542,099 12/ 1941 Great Britain.

679,940 9/ 1952 Great Britain.

5 ROBERT S. WARD, JR., Primary Examiner U.S. Cl. X.R. 

